The former director of rugby at Harlequins, Dean Richards. Photograph: Matthew Lewis/Getty Images

Dean Richards, who resigned as Harlequins' director of rugby earlier this month after taking responsibility for a fake blood injury at the end of the club's Heineken Cup quarter-final against Leinster last season, was last night banned from coaching for three years after being found guilty of serial cheating, virtually ending any ambition he had of coaching England.

Richards, the 46-year old former England and Lions No8 who had turned Quins into a force in the European game, was last month cleared of a misconduct charge by a disciplinary panel set up to investigate the circumstances of the blood injury suffered by Tom Williams six minutes from the end of the Leinster game when his side trailed by a point which paved the way for the return of the goal-kicker, Nick Evans, who had earlier been replaced and could only return in the event of a blood injury.

But the tournament organisers, European Rugby Cup Ltd, appealed against the decision after a hearing that saw Williams banned for a year and Quins fined £215,000, half of it suspended for two years and no one else held responsible for something that stank of premeditation.

The appeal was held in Glasgow yesterday and lasted nearly 14 hours with half the time taken up by legal argument. The three-man panel heard that Richards, who resigned after a club inquiry earlier this month, had been involved in four similar fabrications and cover-ups and so handed one of the English game's most iconic figures one of the longest suspensions in the history of the professional game.

The club's former physiotherapist, Steph Brennan, who started work with England earlier in the summer, was banned for two years for his part in the scandal but the club's doctor, Wendy Chapman, was cleared because the panel lacked jurisdiction in her case. Quins saw their fine raised to nearly £260,000, payable immediately and in its entirety, while Williams had his ban reduced to four months after admitting that he had been forced to lie and revealing the parts played by Richards and Brennan.

"I deeply regret the role I have played in this unacceptable incident that has done so much damage to the image of rugby union," said the 25-year old wing. "I let down my team-mates and the club fans and I will have to live with those actions for the rest of my career. In deciding to come clean and do the right thing I have honestly tried to rectify this mess and repay the faith shown in me by my friends and family.

"I would like to thank the appeal panel for reducing my sanction but I realise the grave error of judgment that I made. I hope that as a result of this episode no player, or employee, will ever be put in such a compromising position and, if they are, that they always tell the truth, as I wish I had done from the outset."

Richards, whose ban at the moment applies only to competitions run by ERC, who will today ask the International Rugby Board to make the suspension global, admitted organising the fake blood injury and the subsequent cover-up. "I take full responsibility," he said. "It was a farcical situation which did not pan out particularly well. On the day everyone looked at it and thought it was unreal, which was my feeling on the touchline. I had to hold my hand up, but I am not prepared to talk about other incidents."

Quins might have got away from it but for the wink Williams gave to Evans as he left the field. Leinster were furious and tried to get their doctor to check on Williams, but were turned away. It is alleged that when he returned to the dressing room, the inside of Williams's mouth was deliberately cut to add to the pretence that he had been injured and had not bitten on a blood capsule.

The disciplinary panel which heard the case last month imposed a draconian punishment on Williams because only his guilt was proved, but the outcry which blew up was followed by an investigation by Harlequins. Williams said he was going to tell the truth and Richards submitted his resignation on the day that Williams appealed and ERC contested the exoneration of Richards, Brennan and Chapman on the misconduct charge.

Quins are fortunate not to have been thrown out of the Heineken Cup, saved probably by the imminent start of the season, but the club issued a statement last night claiming the punishment had been severe. It ran: "While the club are pleased that Tom Williams's ban has been reduced, we feel this is a very significant penalty in terms of fine. We will now continue with our internal review into all aspects of the business to ensure that we have the most stringent compliance and robust policies and processes in place throughout the club and work towards rebuilding our reputation on and off the field. We hope that the club can now draw a line under what has been a difficult few months, learn from it and move on."

No mention was made of Richards, who helped transform Quins from a first division club to one which made the knock-out stage of the Heineken Cup for the first time after success as a player and coach at Leicester, but it may not be the end for Quins. The panel heard that Richards and Brennan had fabricated blood injuries in four other matches, none of them run by ERC, and that details would be passed on to the organisers of those tournaments, opening the door for a Rugby Football Union investigation if Premiership matches are among them.